I'm pretty sure that a mini contract is about 1/5 of a regular contract and the 'e' stands for electronic entry as opposed to a floor trade. Call me newbie too if ya wanna. That's what Iv'e been calling myself for a couple of years.

plum is correct.. they are electronically traded mini (referring to the margin requirement) contracts on S&P500, nasdaq-100, and dow indexes. i don't know of any other e-minis.. the reason they are so popular (or getting that way anyway) is:

high leverage + high liquidity. you can easily make/lose 25% in a day

they all trade on globex (or cbot) -- no multiple markets

no downtick rule

better tax treatment. file your total P/L and pay 40% as long term gains and 60% as short term gains.